The present invention relates to a switch, and in particular to a switch for a flashlight.
Flashlights are available in a wide variety of shapes and sizes, and tailored to a particular use or situation. However, two desires that continue to indicate the need for improved flashlights include the desire for small flashlights and longer useful life. For example, there is a desire for a flashlight that is of a size and shape to conveniently fit in a pocket, e.g., a shirt pocket. In addition, there is a desire for a flashlight that has a bright beam and that operates for a long time before needing to replace or recharge the battery. Also, consumers also want such flashlights to be durable and available at a reasonable cost.
Prior art pocket lights such as a typical pen-shaped light typically are about 1.3 to 2 cm in diameter and are quite heavy, principally due to the size and weight of the type AA (about 1.4 cm diameter) or type AAA (about 1 cm diameter) batteries therein. It would be desirable to have a flashlight of about 1 cm or less in diameter, which is closer to the diameter of typical pens and pencils also kept in a person""s pocket. A further advantage of a smaller-diameter flashlight is the ability to shine the light into small spaces.
The desire for a small-diameter flashlight makes the inclusion of complex internal current-carrying conductors undesirable because they tend to increase the diameter of the light, as well as adding cost thereto, i.e. cost for material, cost for fabrication of the internal parts, and added cost for assembly of the flashlight.
Prior art flashlights typically employ filament-type lamps that have a filament that is electrically heated to glow to produce light, wherein the filament is suspended between supports. Typical filaments tend to be fragile, and often more so when they are heated to glowing. As a filament is used, the filament material may thin or become brittle, thereby increasing its susceptibility to breakage. Even high-light-output lamps such as halogen and xenon lamps employ a heated filament, albeit a more efficient light producer than is a conventional incandescent lamp filament. A solid-state light source, such as a light-emitting diode (LED), for example, does not have a heated filament and so is not subject to the disadvantages associated with lamp filaments, and such LEDs are now available with sufficiently high light output as to be suitable for the light source for a flashlight.
A simple switch is desired for the foregoing and other flashlights, and for utilization in other apparatus. Accordingly, there is a need for switch that is simple and can be made at a reasonable cost.
To this end, the switch of the present invention comprises a hollow cap engaging the end of a housing, a pushbutton in the cap and movable axially therein, and a metal electrical contact having a circular periphery and a central opening. The metal electrical contact engages the pushbutton and is movable axially in the cap to selectively contact the end of the housing for making selective electrical contact therewith. A coil spring is disposed axially for urging the metal electrical contact away from the housing in the cylindrical cap.
According to another aspect of the invention, a switch assembly comprises a pushbutton having an outward flange and a body portion of lesser diameter than the flange thereof, wherein the pushbutton is electrically insulating, and a metal electrical contact having an outward circular contact flange and having a central opening therethrough. The metal electrical contact engages the pushbutton, and an electrically conductive coil spring is disposed axially with respect to the pushbutton and extends into the central opening of the metal electrical contact for electrically contacting the metal electrical contact. The coil spring is for urging the metal electrical contact and the pushbutton in the same direction.